The JSS problem requires a number of jobs to be processed on several machines such that an objective function is optimised. In this context, a job consists of a number of operations, and each operation must be executed on a specific machine. In JSS, the execution of operations on machines (routes) are fixed and can be different for different jobs [1]}. In this study, the focus is on the static JSS problem, where a schedule for the shop (the working/manufacturing environment) must be determined, with the shop consisting of a set of \(M\)  machines and \(N\)  jobs. A job \(j\)  has a fixed route through the machines, and the processing times are different at each machine it visits. [id=AE,comment=I think this should not include \(prec\)  for precedence constraints, despite the mention of precedences below(?) ]In the notation of [2]} this scheduling problem is \(J | r_j | Obj\)  where \(Obj\)  is one of \(C_{\max }\) , \(T_{\max }\)  or \(\sum w_jT_j\) .
